The wheel is an ancient device dating back from 3500 to 3000 B.C. and has been used for many purposes such as carts, potters wheel, spinning wheel, water wheel, windmill, pulley, gears, the vehicular wheel on bicycles, motorcycles, cars, trains, trailers, and other vehicles of all types. There are many types of wheels, large, small, thick, thin, round, square, rectangular, elliptical, and oval. The most used wheel configuration is circular, but other shapes are in use.
One of the primary limitations of the conventional wheel is that it is designed for the efficient use for travel on a particular surface at a specific speed range where upon moving onto another type of surface, speed, smoothness of riding across, and the efficiency of the common wheel drops considerably or, on many occasions it will be of no use whatsoever. For example: the wheel of a racing car is designed for high speed, with minimal road contact on straight runs, but enough contact for having adequate friction to make controlled high speed turns on curves. The road surface on which the race car rides is generally relatively smooth and hard, such as asphalt and concrete. As the race car is driven onto a differing surface, such as a soft dirt road or rocky country road, the very efficient wheel of the race car suddenly becomes a burden, very inefficient, even unstable, unless exchange to off-road wheels are made to adapt to the new surface conditions. Similarly, the wheels of an off-road vehicle are excellent for an off-road environment such as a soft, sandy, or gravely surface. Driving onto a hard, smooth, road surface however, the off-road wheels become a liability, preventing high road speed and providing a bumpy ride.
Unique improvements have been sought and found, some with excellent features. U.S. Pat. No. 3,459,454 discloses an elliptical wheel having excellent shape characteristics for riding over a soft media surface. U.S. Pat. No. 3,620,278 is another example of a distinguished wheel featuring some configuration variability to broaden the wheel footprint on the ground surface to increase traction. There remains, however, a need for other wheels possessing the flexibility to provide superb riding conditions even as terrain conditions vary severely. This invention overcomes this handicap eloquently. As terrain conditions change, adjust the wheel to one of multiple available shapes applicable for maximum efficiency and smooth riding for each distinctive surface condition.
Other purposes of the wheel in form of pulley and gears is to transmit rotational power from one shaft to another, from one gear to another, from one pulley to another, or to transmit rotational power through use of belts, chains, or similar power transmission extensions.